The invention generally relates to a warning device for the detection of the presence of combustion products and, more particularly, to a smoke and fire detector for installation in remote and generally inaccessible spaces.
Smoke and fire detectors are manufactured in a great variety of configurations. Many are provided with an ionization chamber or photocell for detecting combustion product particles in the air. Most of the detectors designed to be installed in a previously existing structure are powered by a battery making them portable. Thus, the detectors can be installed as required in the areas of a building where persons live and/or work.
In order to obtain maximum protection, it is necessary to install detectors at various locations in a house or commercial building. These detectors are typically mounted where they can be easily reached for checking the operation and where the warning sound can be easily heard by the occupants of the building.
Each year, many fires start in areas which are inaccessible or remote from the living or working areas of a building. For example, the attic of a home typically contains combustible materials and electrical wiring or other potential fire initiating elements. An attic fire can burn for some time before it breaks through the ceiling or walls to be sensed by a detector mounted in the living area.
U.S. Pat. No. 3,984,826 discloses a detector for detecting conditions in more than one region. The detector includes a pilot flame established by a controlled supply of fuel connected to a burner at the bottom of a vertically elongate chimney. The chimney is closed at the bottom and combustion air for the flame enters the top of the chimney and flows downwardly therein. The flame is extinguished, or diminished, when combustion products or gases other than oxygen enter the upper end of the chimney and reduce the supply of oxygen to the flame. A flame detecting device adjacent the pilot flame burner is activated in response to extinguishing, or diminishing of the flame and can be connected to cause a signal, such as an alarm, to be actuated. The detector is mounted in an enclosure and ducts lead from the enclosure to regions which are to be monitored by the detector whereby the gases from the regions influence the detector.
U.S. Pat. No. 4,319,234 discloses a smoke detector having a sensor and a power source mounted in a housing attached to one arm of a generally U-shaped downwardly directed bracket. The other arm of the bracket carries a second sensor interconnected with the first sensor and the power source whereby the bracket is adapted to be placed over the top of a door such as a hotel room door. The second sensor monitors the hallway while the first sensor monitors the interior of the room.
U.S. Pat. No. 4,481,502 discloses a central smoke detection system for a building having multiple rooms. A low cost commercial smoke detector is utilized in each room and a central power source supplies power to all the detectors via a common lead and a separate power lead to each detector.